Hood

ABSTRACT

Air is circulated through an area overlying a predetermined portion of a horizontal work surface such as a laboratory table while both enclosing confinement of the area and opening thereof to receive portions of objects supported in part by other portions of the work surface are selectively accommodated by a hood having movable side panels. In another aspect of the invention, a range of selected atmospheric conditions in the area are achieved by controlling the condition of the air being circulated.

United States Patent [191 Mayberry [451 July 17,1973

l l HOOD [75] Inventor: Lee G. Mayberry, Indian Trail, NC.

{73] Assignee: MayRich Specialty Company, Indian Trail, NC.

[22] Filed: Aug. 13, 1971 [21] Appl. No.: 171,454

[52] US. Cl 98/115 LH, 98/33 R [5 1] Int. Cl; F23] 11/00 [58] Field of Search 98/115 R, 115 LH,

[56] References Cited UNITED STATES PATENTS 2,715,359 8/1955 Mackintosh et al 98/115 LH 3,021,776 2/1962 Kennedy 98/115 LH 2,702,505 2/1955 Nelson 98/115 LH Ana SuPPLY FROMBUILNNG l/l966 Berger, Jr. 98/l l5 LH 4/l970 Greer 98/l l5 LH Primary Examiner-Meyer Perlin Assistant Examiner-Ronald C. Capossela Attorney-Warley l... Parrott, Daniel E. McConnell,

et al.

[57] ABSTRACT 12 Claims, 6 Drawing Figures PAINTED- sum 1 or 3 FROM BUILNNG An: SUPPLY BurLbmG EXHAUST HOOD Prior experience with a variety of facilities, and particularly with laboratory facilities where experiments are carried forward, has developed technology relating to the control of noxious or objectionable fumes and the like. Conventionally, such problems are resolved through the use of a hood, through which a flow of air is induced. By such a flow of air through the hood,

fumes and the like are withdrawn from a working area.

Particularly with relation to laboratory hoods, it has become conventional practice to either construct an auxiliary hood used in conjunction with a horizontal work surface such as a laboratory table where relatively confined experiments are to be conducted or, in the alternative, to construct a large cabinet like hood in instances where large objects or experiments must be accommodated. While the smaller accessory hood in many instances has been an acceptable solution for the problems of circulating air through an experimental area or work area, the expense of large cabinet hoods and the difficulty encountered in providing proper support for experiments or objects therewithin has made this solution less than satisfactory.

It is an object of the present invention to overcome the shortcomings and deficiencies of prior hood arrangements, through a novel and unusual selective accommodation both of enclosing confinement of a work area and opening thereof to receiving portions of objects supported in part by other portions of a horizontal work surface lying outside the work area. In realizing this object of the presentinvention, advantage is taken over a novel arrangement of side panel means movable relative to a main hood casing between an enclosing position wherein the side panel means cooperate in confinement of a work area and an open position wherein an object supported in part by other portions of a work surface may project into the work area.

Yet a further object of the present invention is to control atmospheric conditions within the work area by controlling the conditions of the air circulating therethrough. In realizing this object of the present invention, condition modifying means are incorporated into a means which induces a flow of air through the hood, for controlling at least one characteristic condition of the flow of air, such as temperature.

Some of the objects and advantages of the invention having been stated, others will appear as the description proceeds, when taken in connection with the accompanying drawings, in which FIG. 1 is a perspective view of an arrangement in accordance with the present invention;

FIG. 2 is a view similar to FIG. 1, illustrating the arrangement of the present invention as prepared to accommodate a large object;

FIG. 3 is a plan view, in section, through portions of the apparatus of FIGS. 1 and 2, taken generally as indicated by the line 3'-3 in FIG. 1;

FIG. 4 is a view similar to FIG. 3, takengenerally as indicated by the line 4--4 in FIG. 2;

FIG. 5 is an elevation view, partially in section, taken generally as indicated by the line 5-5 in FIG. 1; and

FIG. 6 is an elevation view, in partial section, taken generally as indicated by the line 6-6 in FIG. 1.

In the following detail disclosure of the present combination, given with particular reference to the drawings, the specific arrangement of a hood generally indicated by the reference character 10 with a horizontal work surface such as a laboratory table generally indicated by the reference character 11 will be described. It is to be noted at the outset of this disclosure that, while a specific embodiment of the present invention has been illustrated and will be described, this disclosure is to be taken as illustrative of the present invention only, rather than as limiting the forms which the invention may take, which may by way of example include walk-in hoods and double-faced hoods for use without counters or with center tables. The hood 10 includes a main hood casing 12 supported from the building walls or overhead and generally overlying a predetermined portion of the work surface 11, with the main hood casing 12 including a head portion 14 and a back wall portion 15 (FIG. 5). Side panel means comprising a left-hand panel member 16 and a right-hand panel member 18 extend vertically adjacent the work surface 11 and are operatively connected to the main hood casing 12 for movement relative thereto.

In particular, and in accordance with an important feature of the present invention, the left-hand panel member 16 and the right-hand panel member 18 are individually movable between respective enclosing positions (FIGS. 1, 3, 5 and 6) and open positions (FIGS. 2 and 4). When the side panel members 16, 18 are in the enclosing positions, the side panel means cooperate in confinement of the area underlying the head portion 14 of the main hood casing 12. With movement of the side panel members to the open position, access to the area may be gained and the area is opened to receive portions of objects supported in part by other portions of the work surface 11. By way of example, an elongate object may be arranged on the work surface 11 with a portion thereof extending into the work area for experimentation. It is to be noted that, through the provision of two panel members 16, 18, movement thereof between respective enclosing and open positions will accommodate selection of enclosure of the area, partial opening thereof, and full opening thereof.

The side panel means is hingedly connected to the main hood casing by the provision of hinge members (the hinge member 19 for the left-hand panel member 16 being shown in FIGS. 3 and 4). By the hinged connection of the panel means with the main hood casing 12, and particularly with the back wall portion 15, the panel members 16, 18 are arranged for disposition underlying the head portion 14 when in the enclosing position and for pivoting movement to the open position, in which the members are disposed extending outwardly from the main hood casing. Preferably, the pins of the hinge members such as the member 19 may be removable, to permit removal of the panel members 16, 18 and use of the hood as a canopy hood. Each of the side panel members 16, 18 is formed by a corresponding plurality of spaced sheet members (such as the outside sheet member 20, the end: sheet member 21 and the inside sheet member 22, which together make up the left-hand side panel member 16 as shown in FIG. 3) so that the side panel members enclose a hollow interior for purposes to be made more apparent in the description which follows.

The hood 10 further includes a front panel means 24 extending vertically adjacent the work surface 11 and being operatively connected with the main hood casing 12 for movement relative thereto between an enclosing position and an open position. Such front panel means have been used heretofore with conventional accessory hoods, and thus are generally known. Consistent with usual practice, it is preferred that the front panel means 24 include a window portion through which the progress of any experiment conducted within the hood may be observed while the observor is protected. In any event, the front panel means 24 cooperates in confinement of the work area when in the lowered, enclosing position and permits access to be gained to the work area when in an open or raised position.

Optionally means may be provided for maintaining the hood in a closed position when desired. In the illustrated embodiment, such means may take the form of thumb operated latches (not shown) mounted on the side panel members 16, 18 and engaging the main hood casing 12 when the side panel members are moved to a closed position. Such latches, on engaging the main hood casing, will retain the panel members in closed position until manually released. The front panel means 24 preferably is provided with a keyed lock (not shown) which may be operated to lock the front panel means 24 in lowered position and thereby secure the hood against unauthorized use.

In order to remove fumes and the like from the work area, means are provided for inducing a flow of air through the main hood casing 12 and into, through and out of the work area. In the embodiment illustrated, the means for inducing a flow of air includes an exhaust conduit 25 operatively communicating with an exhaust fan (indicated in FIG. I); and optionally further includes a first conduit means 26 for delivering to the hood means 10 a flow of air at conditions substantially corresponding to ambient air conditions around the work surface 11 and a second conduit means 28 for delivering to the hood means 10 a flow of air at conditions differing from such ambient air conditions. As will be described more fully hereinafter, the present invention contemplates that atmospheric conditions within the working area may be controlled by controlling at least one characteristic condition of the incoming flow of air, such as temperature.

Operatively communicating with the first conduit means 26 is a supply fan (not shown) for delivering therethrough air from the conditioned supply of air to the room containing the hood 10, such as a central air conditioning system, or from without the building, as may be described. Operatively communicating with the second conduit means 28 is a condition modifying means generally indicated at 29. In the form illustrated, the condition modifying means 29 incorporates a blowing fan 30, a first heat exchanger 31 and a second heat exchanger 32. Desirably, the first heat exchanger 31 is operatively connected with an expansion cycle refrigeration plant, to exchange heat with air flowing therethrough and cool the air. By way of contrast, the second heat exchanger 32 is desirably connected with a steam generator or is otherwise heated to exchange heat with air flowing therethrough and raise the temperature thereof. By controlling the temperatures of the heat exchangers 31, 32 with relation to air flowing therethrough, the temperature condition of the air may be controlled so that a flow of air is delivered to the hood which is at conditions differing from those ambient to the work surface 11. That is, an experiment conducted within the hood may be conducted in an elevated temperature atmosphere or in a reduced temperature atmosphere, as may be required. While not herein illustrated, the present invention contemplates that the condition modifying means 29 may incorporate humidity control means as well, to control the humidity condition of the incoming flow of air.

In event of emergency, the supply fans delivering air through the conduit means 26, 28 may be reversed, so that all air flow is from the hood to more quickly remove fumes therefrom.

In order to provide for selective control over air delivered to the hood 10, valve means are provided in the first and second conduit means 26, 28 for governing flow of air therefrom to the hood 10. In particular, damper valve members 34, 35 are positioned respectively in the first and second conduits, and are coupled by an operating cross-like member 36. Desirably, positioning of the valve members 34, 35 is accomplished by a control motor 38 linked to the link member 36.

The hood 10 further includes flow directing means therewithin which define passageways for directing the flow of air induced therethrough. In the illustrated embodiment, air delivered from the first and second conduits 26, 28 passes through a dividing conduit 39a, 39b to be delivered into opposite side edge portions of the head portion 14 of the main hood casing 12. As illustrated by arrows in FIG. 6, air passing into the hood 10 through the delivery conduits 39a, 39b enters into passageways 40a, 40b in the head portion 14 which overlie the side panel members 16, 18. Air flowing in the passageways 40a, 40b reaches flexible conduits 41a, 41b which establish operative communication between the passageways 40a, 40b and the holloe interiors of respective side panel members 16, 18. In this manner, air flowing within the hood 10 is directed into the side panel members 16, 18. Each of the side panel members l6, 18 includes outlet grill means respectively indicated at 42a, 42b, for delivering into the work area the flow of air induced to pass through the hood .10.

It will be further noted that the flow directing means within the main hood casing includes a false back wall 44 and upper walls 45, 46. By means of ports in the false rear wall 44 and rear upper wall 45, together with adjustable closure members 48, 49 mounted adjacent the ports, the amount of free area through which communication from the work area to the exhaust conduit 25 is achieved may be controlled. Thus, the extent to which the exhaust fan draws air from within the work area may be controlled. As indicated by arrows in FIG. 5, air discharged from the outlet grills 42a, 42b moves through the work area and passes therefrom to the exhaust conduit 25. 4

In order to permit use of various services in the work area, the present invention contemplates a novel arrangement for delivery of service fluids thereinto. In particular, service fluids such as combustible gas to be. delivered to a Bunsen burner or the like, compressed air and so forth are delivered to valve means mounted in the side panel members 16, 18 for controlling flow of such auxiliary service fluids. By way of example, combustible gas may be delivered by supply connections from an appropriate source to flexible conduit means 50 (FIGS. 3 and 4) extending from the back wall portion 15 of the main hood casing 12 into the side panel members and being operatively connected with a control valve 51. The flexible conduit means 50 are provided -.with quick disconnect couplings of known types (not shown) in instances where removable hinge pins are used as disclosed above. By means of a valve stem 52 extending through an end panel member 21 remote from the location of hinged interconnection of the side panel with the back wall portion of the main hood casing 12 and a manually operable valve handle 54 secured to the terminal end of the stem 52, a user of the hood may control the flow of auxiliary service fluid through the valve 51 and a tubular outlet 55 communicating therewith. As indicated in FIGS. 1, 2 and 6, a pluralityof such services may be provided if desired to accommodate such number of auxiliary service fluids as are desirable for a particular hood installation.

In operation of the combination of the present invention, an experiment which may be conducted within the confined space of the work area may be carried forward by opening the front panel member 24 to gain access to the work area, installing the necessary equipment or positioning the necessary objects, and proceeding with the experiment. Air flow into, through and from the work area would be as described above with particular reference to FIGS. 3, 5 and 6. In an instance where an object or experiment need, be accommodated by opening of the work area, one or both of the side panel members 16, 18 is moved to the extended position of FIGS. 2 and 4. As so arranged, air may flow into the work area either from the discharge outlets 42a, 42b in the side panel members 16, 18 or from an air barrier boundary provided by auxiliary outlet means 56a, 56b included in the head portion 14 of the main hood casing means 12.

In particular, the auxiliary outlet means 56a, 56b are mounted in the head portion 14 and positioned to overlie the side panel members 16, 18 when the same are in the enclosing positions. The auxiliary air outlet means 56a, 56b operatively communicate with the main hood casing passageways 40a, 40b for directing a portion of an induced air flow downwardly toward the work surface (FIG. 2) when the corresponding side panel member is in the opened position. Desirably, a manually controlled shutter is provided in the secondary air outlet means 56a, 56b, to permit selection of the division of the air flow between the side panel members and the air barrier boundary.

In the drawings and specification, there has been set forth a preferred embodiment of the invention, and although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation.

That which is claimed is:

l. The combination with a horizontal work surface such as a laboratory table of means for circulating air through an area overlying a predetermined portion of the work surface while selectively accommodating both enclosing confinement of said area and opening thereof to receive portions of objects supported in part by other portions of the work surface, said air circulating means comprising: i

a main hood casing generally overlying said predetermined portion of the work surface,

side panel means extending vertically adjacent the work surface and operatively connected with said main hood casing for movement relative thereto between an enclosing position wherein said side panel means cooperates in confinement of said area and an open position wherein an object supported in part by other portions of the work surface may project into said area,

front panel means extending vertically adjacent the work surface and operatively connected with said main hood casing for movement relative thereto between an enclosing position wherein said front panel means cooperates in confinement of said area and an open position wherein access to said area may be gained, and

means for inducing a flow of air through said main hood casing and into, through and out of said area.

2. The combination of claim 1 wherein said side panel means comprises a left-hand panel member and a right-hand panel member, said panel members being individually movable between respective enclosing and open positions for accommodating selection of enclosure of said area, partial opening thereof and full opening thereof.

3. The combination according to claim 1 wherein said air flow inducing means includes means for delivering to said main hood casing conditioned air having predetermined characteristics so as to provide a controlled atmosphere in said area.

4. The combination according to claim 1 wherein said main hood casing includes a head portion and a back wall portion and further wherein said side panel means is operatively connected for disposition underlying said head portion when in said enclosing position.

5. The combination according to claim 4 wherein said side panel means is hingedly connected with said back wall portion for disposition extending outwardly from said main hood casing when in said open position.

6. The combination according to claim 1 wherein said main hood casing includes a head portion and a back wall portion and further wherein said side panel means is hingedly connected with said main hood casing for disposition underlying said head portion when in said enclosing position and for pivoting movement to said open position.

7. The combination according to claim 6 further comprising flow directing means dlefining passageways within said main hood casing for directing said flow of air induced therethrough and flexible conduit means operatively communicating with said pasageways and connected with said side panel means for selectively directing flow of air into said area from said side panel means.

8. The combination with a horizontal work surface such as a laboratory table of means for circulating air through an area overlying a predetermined portion of the work surface while selectively accommodating both enclosing confinement of said area and opening thereof to receive portions of objects supported in part by other portions of the work surface, said air circulating means comprising:

a main hood casing including a head portion generally overlying said predetermined portion of the work surface and a back wall? portion extending vertically adjacent the work surface,

side panel means including at least one side panel member hingedly connected to said main hood casing for movement relative thereto between an enclosing position underlying said head portion and extending vertically adjacent the work surface and an open position wherein an object supported in part by other portions of the work surface may project into said area,

front panel means extending vertically adjacent the work surface and operatively connected with said main hood casing for movement relative to said side panel means and said main hood casing between an enclosing position and an access position, and means for inducing a flow of air into, through and out of said area and including air flow directing means defining passageways within said main hood casing for directing therethrough an induced flow of air. 9. The combination according to claim 8 further comprising air flow directing means mounted in said head portion of said main hood casing and positioned to overlie said side panel member when the same is in said enclosing position, said air flow directing means operatively communicating with said main hood casing passageways for directing a portion of said induced flow of air downwardly toward the work surface when said side panel member is in said open position and thereby for providing an air barrier boundary for said area.

10. The combination according to claim 8 further comprising flexible conduit means extending between said at least one side panel member and said main hood casing for operatively communicating a fluid flow to said side panel member.

11. The combination according to claim 10 wherein said side panel member comprises a plurality of spaced sheet members enclosing a hollow interior and air flow directing means mounted in one of said sheet members for directing a flow of air toward said predetermined portion of the work surface, and further wherein said flexible conduit means establish operative communication between said main hood casing passageways and said side panel member hollow interior.

12. The combination according to claim 10 further comprising valve means mounted in said side panel member for controlling flow of auxiliary service fluids such as combustible gas and the like, and further wherein said flexible conduit means establish operative communication with said valve means for delivering said fluids thereto. 

1. The combination with a horizontal work surface such as a laboratory table of means for circulating air through an area overlying a predetermined portion of the work surface while selectively accommodating both enclosing confinement of said area and opening thereof to receive portions of objects supported in part by other portions of the work surface, said air circulating means comprising: a main hood casing generally overlying said predetermined portion of the work surface, side panel means extending vertically adjacent the work surface and operatively connected with said main hood casing for movement relative thereto between an enclosing position wherein said side panel means cooperates in confinement of said area and an open position wherein an object supported in part by other portions of the work surface may project into said area, front panel means extending vertically adjacent the work surface and operatively connected with said main hood casing for movement relative thereto between an enclosing position wherein said front panel means cooperates in confinement of said area and an open position wherein access to said area may be gained, and means for inducing a flow of air through said main hood casing and into, through and out of said area.
 2. The combination of claim 1 wherein said side panel means comprises a left-hand panel member and a right-hand panel member, said panel members being individually movable between respective enclosing and open positions for accommodating selection of enclosure of said area, partial opening thereof and full opening thereof.
 3. The combination according to claim 1 wherein said air flow inducing means includes means for delivering to said main hood casing conditioned air having predetermined characteristics so as to provide a controlled atmosphere in said area.
 4. The combination according to claim 1 wherein said main hood casing includes a head portion and a back wall portion and further wherein said side panel means is operatively connected for disposition underlying said head portion when in said enclosing position.
 5. The combination according to claim 4 wherein said side panel means is hingedly connected with said back wall portion for disposition extending outwardly from said main hood casing when in said open position.
 6. The combination accorDing to claim 1 wherein said main hood casing includes a head portion and a back wall portion and further wherein said side panel means is hingedly connected with said main hood casing for disposition underlying said head portion when in said enclosing position and for pivoting movement to said open position.
 7. The combination according to claim 6 further comprising flow directing means defining passageways within said main hood casing for directing said flow of air induced therethrough and flexible conduit means operatively communicating with said pasageways and connected with said side panel means for selectively directing flow of air into said area from said side panel means.
 8. The combination with a horizontal work surface such as a laboratory table of means for circulating air through an area overlying a predetermined portion of the work surface while selectively accommodating both enclosing confinement of said area and opening thereof to receive portions of objects supported in part by other portions of the work surface, said air circulating means comprising: a main hood casing including a head portion generally overlying said predetermined portion of the work surface and a back wall portion extending vertically adjacent the work surface, side panel means including at least one side panel member hingedly connected to said main hood casing for movement relative thereto between an enclosing position underlying said head portion and extending vertically adjacent the work surface and an open position wherein an object supported in part by other portions of the work surface may project into said area, front panel means extending vertically adjacent the work surface and operatively connected with said main hood casing for movement relative to said side panel means and said main hood casing between an enclosing position and an access position, and means for inducing a flow of air into, through and out of said area and including air flow directing means defining passageways within said main hood casing for directing therethrough an induced flow of air.
 9. The combination according to claim 8 further comprising air flow directing means mounted in said head portion of said main hood casing and positioned to overlie said side panel member when the same is in said enclosing position, said air flow directing means operatively communicating with said main hood casing passageways for directing a portion of said induced flow of air downwardly toward the work surface when said side panel member is in said open position and thereby for providing an air barrier boundary for said area.
 10. The combination according to claim 8 further comprising flexible conduit means extending between said at least one side panel member and said main hood casing for operatively communicating a fluid flow to said side panel member.
 11. The combination according to claim 10 wherein said side panel member comprises a plurality of spaced sheet members enclosing a hollow interior and air flow directing means mounted in one of said sheet members for directing a flow of air toward said predetermined portion of the work surface, and further wherein said flexible conduit means establish operative communication between said main hood casing passageways and said side panel member hollow interior.
 12. The combination according to claim 10 further comprising valve means mounted in said side panel member for controlling flow of auxiliary service fluids such as combustible gas and the like, and further wherein said flexible conduit means establish operative communication with said valve means for delivering said fluids thereto. 